NIH has identified weight loss maintenance as the next major challenge in obesity treatment. Continuous care models that involve ongoing patient-professional contact yield promising maintenance outcomes. However, the traditional approach to providing continuous care (professional staff) is costly and thus unsustainable. Patient-delivered interventions (in which trained patients deliver treatment) may be a unique solution to providing continuous care at low cost and with organic sustainability. Moreover, qualitative data suggest that, given their shared experience, fellow patients have a unique sense of empathy not duplicated by professionals, family or friends. Thus, patient-delivered treatment may be a uniquely powerful, sustainable, and cost-effective treatment experience. However, patient-delivered treatment has never been tested for continuous care and has never been evaluated for weight loss maintenance. The proposed study will, for the first time, test patient-delivered treatment for weight loss maintenance. Our preliminary data demonstrate that our team is highly effective at engaging, retaining, and providing evidence-based training to patient providers, evidenced by 12-month engagement and retention rates between 88 and 100%. Moreover, in a recent trial, we showed that during the initial maintenance phase (when weight regain is common) trained patient providers yielded additional weight loss. Thus, in this trial, participants will be randomized to either patient-delivered care or current best practice. Weight loss maintenance will be examined at month 18. Given that trained patients will provide weekly ongoing evidence-based treatment, our primary hypothesis is that patient-delivered treatment will yield better weight loss maintenance outcomes at 18-months compared to current best practice (i.e., which involves tapered contact ? i.e., weekly, bimonthly, monthly). In addition to this trial being the first to test the long-term efficacy of patient providers for maintenance, it will also be the first to (1) train patient providers to deliver ALL treatment components (previous trials relied on a hybrid approach in which professionals and patients co-delivered treatment); (2) examine the long-term sustainability of patient-provided treatment once formal treatment ends (patients? continued correspondence via email or text will be examined); (3) explore the unique mechanisms (empathy, inspiration, hope, compassion) by which patient-provided care exerts its effects; and (4) examine the cost-effectiveness of patient-provided treatment vs. current best practice. If effective, this study would demonstrate that patient-provided care is a new and transformative intervention approach that provides continuous care in a sustainable, cost-effective manner.